1. Field of the Invention
The present invention relates to an electrical contact, and particularly to an electrical contact for surface mounting to a printed circuit board whereby excess solder will not hinder signal transmission.
2. The Prior Art
The trend of the computer industry continues toward miniaturization. Notebook and hand held computers both require an efficient use of internal space to include the necessary hardware within a housing of limited size. In desktop computers, a printed circuit board (PCB) is commonly provided with through holes for connecting components on one surface with components on the opposite surface of the PCB. However, such through holes occupy too much space on the PCB. Therefore, a surface mounting contact 4, as shown in FIGS. 3 and 4, has been introduced for surface mounting to both sides of a PCB 3.
The contact 4 includes a contacting end 41 for electrically engaging with a contact pad formed on an electrical card (not shown), a tail 42 opposite the contacting end 41 for surface mounting to the PCB 3, and a retaining portion 43 formed between the contacting end 41 and the tail 42 for retention in a housing 33 of an SO DIMM connector. A continuous face 44 is formed between the tail 42 and the contacting end 41 opposite the retaining portion 43. The tail 42 is electrically engaged with a contact pad 31 on the PCB 3 by means of solder 32. After surface mounting of the connector to one side of the PCB 3, the PCB 3 with the associated connector is handled in an upside-down manner to surface mount other components on the other side of the PCB, so that liquefied solder or excess solder 32 has a tendency, due to gravity, to flow downward along the continuous face 44 and cover a substantial portion of the contacting end 41. Since the contacting end 41 is gold-coated for facilitating high speed signal transmission, the excess solder 32 formed on the contacting end 41 will hinder signal transmission.
Hence, an improved electrical contact is needed to overcome the disadvantages of surface mount soldering conventional electrical contacts.